# 19 19 25 triangle

### Acute isosceles triangle.

Sides: a = 19   b = 19   c = 25

Area: T = 178.8643600266
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 48.86604895851° = 48°51'38″ = 0.85327764174 rad
Angle ∠ B = β = 48.86604895851° = 48°51'38″ = 0.85327764174 rad
Angle ∠ C = γ = 82.27990208298° = 82°16'44″ = 1.43660398188 rad

Height: ha = 18.82877473964
Height: hb = 18.82877473964
Height: hc = 14.30990880213

Median: ma = 20.06986322404
Median: mb = 20.06986322404
Median: mc = 14.30990880213

Inradius: r = 5.67882095322
Circumradius: R = 12.61443608686

Vertex coordinates: A[25; 0] B[0; 0] C[12.5; 14.30990880213]
Centroid: CG[12.5; 4.77696960071]
Coordinates of the circumscribed circle: U[12.5; 1.69547271527]
Coordinates of the inscribed circle: I[12.5; 5.67882095322]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 131.1439510415° = 131°8'22″ = 0.85327764174 rad
∠ B' = β' = 131.1439510415° = 131°8'22″ = 0.85327764174 rad
∠ C' = γ' = 97.72109791702° = 97°43'16″ = 1.43660398188 rad

# How did we calculate this triangle?

Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS. ### 1. The triangle circumference is the sum of the lengths of its three sides ### 2. Semiperimeter of the triangle ### 3. The triangle area using Heron's formula ### 4. Calculate the heights of the triangle from its area. ### 5. Calculation of the inner angles of the triangle using a Law of Cosines ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.